leveldb

LevelDB Cache Example

This example demonstrates using httpcache with LevelDB for high-performance persistent storage.

Features Demonstrated

• Creating a LevelDB-based cache
• Fast persistent storage
• Caching multiple URLs
• Cache size monitoring

Running the Example

From the project root directory:

go run ./examples/leveldb/main.go

Or from the examples/leveldb directory:

go run main.go

Use Cases

LevelDB cache is ideal for:

• High-performance applications - Faster than regular disk cache
• Embedded systems - No external dependencies
• Desktop applications - Local persistent cache
• CLI tools - Quick startup with cached data
• Offline-first apps - Reliable local storage

Advantages

• Fast: Much faster than disk-based cache
• Persistent: Survives application restarts
• Embedded: No external server needed
• Compact: Efficient storage with compression
• Reliable: Battle-tested database engine

Configuration

cache, err := leveldbcache.New("/path/to/leveldb")
if err != nil {
    log.Fatal(err)
}
transport := httpcache.NewTransport(cache)

Performance Characteristics

• Read latency: ~100µs (much faster than disk cache ~1ms)
• Write latency: Similar to disk cache
• Storage: Compressed, efficient space usage
• Concurrent access: Thread-safe, good concurrent performance

Important Notes

• LevelDB directory must be exclusive to one process
• Not suitable for multiple processes accessing same DB
• Consider periodic compaction for long-running applications
• Database is closed when cache is garbage collected